This invention relates to tape guide assemblies in video tape cassettes.
Video tape cassettes for use in video recording and/or playback machines typically comprise a housing, a predetermined length of magnetic recording tape, and two tape storage reels rotatably mounted in the housing. Each of the reels comprises a hub with each end portion of the tape attached to and wrapped around a different one of the hubs. Each reel has only one tape guide flange which is fixed at one end of its hub, which flange has sufficient diameter to cover the entire side surface of the tape when almost all of the tape is wound around its hub. The reels are mounted in the housing in axially parallel spaced positions with the flanges overlapping and on opposite edges of the tape. The cassette also includes means for defining a tape path between the reels including two tape guide assemblies, one mounted on the housing adjacent each of the reels to guide at least one side surface and the edge opposite the flange of tape being wound on or removed from the reel. Each tape guide assembly includes one arcuate side guide portion for guiding the side surface of the tape and a radially projecting edge guide washer at its end opposite the flange of the adjacent reel which cooperates with that flange to guide tape onto or off of the adjacent reel; and one of the tape guide assemblies has two parallel closely spaced arcuate side guide portions that guide the tape as it passes between them.
In prior art cassettes both the arcuate side guide portions and edge guide washers of the tape guide assemblies are formed of steel, with the side guide portions being attached to the cassette by conventional screws. Thus the tape guide assembly is expensive to make because of the cost of its material and the work required to finish its outer surface and form internal threads, and is time consuming and thus expensive to assemble into a cassette because the screws must be rotated into engagement with it.
Also as the side surface of the tape rubs against the steel side guide portion particles of the tape coating are removed and form debris which, after many uses of the tape, can collect and cause dropouts and other losses of picture clarity in a video recording and/or playback machine in which the cartridge is used.